Grantee Research Project Results
1998 Progress Report: Development of a New Microelectrode Array Biosensing System for Environmental Monitoring
EPA Grant Number: R825323Title: Development of a New Microelectrode Array Biosensing System for Environmental Monitoring
Investigators: Sadik, Omowunmi
Institution: The State University of New York at Binghamton
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1996 through September 30, 1999 (Extended to September 30, 2000)
Project Period Covered by this Report: October 1, 1997 through September 30, 1998
Project Amount: $280,095
RFA: Analytical and Monitoring Methods (1996) RFA Text | Recipients Lists
Research Category: Water , Land and Waste Management , Air , Ecological Indicators/Assessment/Restoration , Environmental Statistics
Objective:
The specific goals of the research project are to utilize conducting polymer-based sensing materials to develop multiarray sensors suitable for monitoring environmental contaminants, and to utilize these sensors for field trial of selected analytes.Progress Summary:
Several environmental and industrial activities are likely to benefit from the rapid information provided by the new, label-free, multianalyte chemical sensors and biosensors. These benefits include bioremediation, human exposure assessment, groundwater monitoring, monitoring of agricultural runoffs, and the detection of early warning signals. The characteristics of the new sensor include small size, fast response times, reversibility, continuous measurement capability, and they are suitable for integration into other devices to allow quick remedial actions to be taken.Although operationally simple, the successful development of a direct, multianalyte sensor is difficult. The problems involved include the difficulties encountered in microfabrication, bioreagent stability, and efficient generation of analyte signals resulting in incomplete or impossible regeneration of sensing surfaces. The overall goal of the project is to develop and conduct field demonstration of a new type of tunable, multianalyte biosensors for environmental analysis using conducting polymer electrode arrays and individually addressable sensing chips. The concept of a multiuse, multianalyte biosensor with no labels and no reversible binding has led to the to the development of new sensors, which can be used to experimentally correlate observed sensor response for several classes of toxic pollutants with absolute concentration levels that can be related to possible sources. This study includes new sensing chemistries based on azo-dyed metal protein conjugates, optimization of instrumental variables, developments of models based on study results, and field testing of the concept developed. Selected priority chemicals that have been studied to date include polychlorinated biphenyls (PCBs) volatile and semivolatile chlorinated phenols, triazines, polyaromatic hydrocarbons (PAHs), and heavy metals.
The theoretical framework used in describing the sensor response was reported for simplified phenolic and hapten-antihapten interactions. The response for several analytes was studied, and the results expressed as IC50 (i.e., 50-percent dose response) values for a range of analytes. The combination of sensor arrays and pattern recognition resulted in a rapid method for the identification and quantitation (IQ) of 2,4-D, 2,4,5 TCP, pentachlorophenol and other organics. The limits of detection (LODs) obtained for 2,4,6-TCP, 2-CP and 2,4-D using 32-array polymer sensors were 0.1, 0.25, and 0.36 ng/mL, respectively. The linear dynamic range of the biosensor was between 0.3?100 ng/mL with a correlation coefficient of 0.997 for Aroclor 1242. The LODs for Aroclors 1242, 1248, 1254 and 1016 were 3.3, 1.56, 0.39, and 1.66 ng/mL respectively, at a signal-to-noise ratio (S/N) of 3. The immunosensor exhibited high selectivity for PCBs in the presence of potential interference such as chlorinated anisoles, benzenes, and phenols. The highest cross-reactivity measured for chlorinated phenolic compounds relative to Aroclor 1248 was less than 3 percent. The recoveries of spiked Aroclors 1242 and 1254 from industrial effluent water, rolling mill, and seafood plant pretreated water at 0.5 and 50 ng/mL ranged from 103 to 106 percent.
The correlation between the IQ levels of bound analytes and the binding capacities was determined by poising the potential to a positive value to measure the interactions. Reversing the applied potential to a more negative value resulted in a regenerated surface of the modified electrodes. Using this routine, the specifically bound analyte molecules are released within minutes and washed out for the next round of interactions. This approach is currently being used to determine a range of quantitative, sensor-activity relationships to be used in predicting sensor behaviors in unknown or complex samples.
Future Activities:
To conduct studies on the kinetics and mechanism of biosensors developed for phenols, PCBs, triazines and heavy metals; continue field demonstration of multiarray sensors developed; utilize the new 4(2) pyridylazo resorcinol (PAR) chemistry for heavy metal monitoring; and conduct comparative studies with existing gas chromotography/mass spectroscopy and immunoassay techniques.Journal Articles on this Report : 9 Displayed | Download in RIS Format
Other project views: | All 70 publications | 9 publications in selected types | All 9 journal articles |
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Bender S, Sadik OA. Direct electrochemical immunosensor for polychlorinated biphenyls. Environmental Science & Technology 1998;32(6):788-797. |
R825323 (1997) R825323 (1998) R825323 (1999) R825324 (Final) |
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Masila M, Sargent A, Sadik OA. Pattern recognition studies of halogenated organic compounds using conducting polymer sensor arrays. Electroanalysis 1998;10(5):312-320. |
R825323 (1997) R825323 (1998) R825323 (1999) |
Exit |
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Sadik OA. Bioaffinity sensors based on conducting polymers: A short review. Electroanalysis 1999;11(12):839-844. |
R825323 (1998) R825323 (1999) |
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Sadik OA, Bender S, Joasil P, Lord J. Electropolymerized conducting polymers as glucose sensors. Journal of Chemical Education 1999;76(7):967-969. |
R825323 (1998) R825323 (1999) |
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Sargent A, Sadik OA. Pulsed electrochemical technique for monitoring antibody-antigen reactions at interfaces. Analytica Chimica Acta 1998;376(1):125-131. |
R825323 (1997) R825323 (1998) R825323 (1999) |
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Sargent A, Sadik OA. Monitoring antibody-antigen reactions at conducting polymer-based immunosensors using impedance spectroscopy. Electrochimica Acta 1999;44(26):4667-4675. |
R825323 (1998) R825323 (1999) |
Exit Exit |
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Sargent A, Loi T, Gal S, Sadik, OA. The electrochemistry of antibody-modified conducting polymer electrodes. Journal of Electroanalytical Chemistry 1999;470(2):144-156. |
R825323 (1998) R825323 (1999) |
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Xu H, Lee E, Sadik OA, Bakhtiar R, Drader J, Hendrikson C. A receptor-based bioassay for quantitative detection of gallium. Analytical Chemistry 1999;71(23):5271-5278. |
R825323 (1998) R825323 (1999) |
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Yan F, Oszoz M, Sadik OA. Electrochemical and conformational studies of microcystin-LR. Analytica Chimica Acta 2000;409(1-2):247-255. |
R825323 (1998) R825323 (1999) |
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Supplemental Keywords:
innovative technologies, environmental contamination, performance-based methods, multianalyte detectors and systems, rapid identification and quantitation techniques, continuous monitoring., RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Environmental Chemistry, Physics, Chemistry, Monitoring/Modeling, Electron Microscopy, Engineering, environmental monitoring, environmental measurement, field portable monitoring, microelectrode, biomonitoring, biosensing system, environmental engineering, spectroscopic, electrochemical analysis, solid waste, groundwaterRelevant Websites:
http://chemiris.chem.binghamton.edu/SADIK/sadik.htmProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.